How are the creases/folds in this mesh for a sofa achieved?
If you would like to achieve this effect with SCULPTING in Blender, a method that would definitely assist you is going to Sculpting &gt;&gt; Tools &gt;&gt; Crease  or using Blender's new Cloth Brushes.
Doing this without sculpting is also probably achievable, you will have to manually tweak the mesh to either pull or push vertices/faces to match the reference.
You also have the option to apply a normal map that has creases but personally I would find that a bit more tidious to do in Blender and would probably still require you to sculpt and bake the map yourself.